Which of the following statements are true about acid-staining of concrete:
A. The typical color range is blue/greens and browns.
B. Fly ash should be limited in the concrete mix to 15 percent maximum.
C. It can be used on old concrete.
D. It affects concrete strength.

Question from Last Week:Architecture Puzzler #300

Diamond, corner, half diamond, blunt ends, and kite are names of the shapes of what type of common building element?